Electric zinc-furnace with integral compound condenser.



J. THOMSON. ELECTRIC zmo FURNACE WITH INTEGRAL COMPOUND CONDENSER.APPLICATION FILED JAN. 2, 1913.

1,080,864 Patenteci Dec. 9, 913.

Whn 655652 Y J. THOMSON. ELECTRIC ZINC FURNACE WITH INTEGRAL. COMPOUNDCONDENSER.

APPLICATION FILED JAN. 2,1913. 1,080,864. I

' pcentea Dec. '9, 1913.

2 SHEETS-SHEET 2.

v Q I Wifnassem LFGHN TK-IGIESON, i315 NE' FY YORK, N.

INTEGRAL CG'MPOUND CONDENSER.

i r. o In meldin -c4111.

Application filed January 2, 1913.

citizen oi. the United States, and. resides" of the borough of Manhattanof the city of New York, in the county and State oi York, have inventedcertain new and ful Improvements in Electric Zinc-Furneces with integralCompound Condensers, or which the following is c. specification,reference beingmade to the uceompenyirg drawings, forming e' perthereof.

This invention relates to the metallurgy of Zinc, having for its objectthe production of zinc fume by thermochemical reaction and thencondensing the turns to liquid metal.

A description of the means at the desired results and such an clue ofgeneral principles applicable ther us will clearly disclose theinvention be concurrently pointed out in connect with the description ofthe ace mpuny drawingsforming av part of this specificstiou and in whichdrawings there is illus trated one embodiment the invention.

In said drawings Figure l is e. iJNl'lSVGFFJQ center section of acombined co and condenser. in the lower or left hand portion of thisfigure the. resistor and charge material have been omitted. 2 is m halttop plan View, as on C, C l, and Fig. 3 is e detached sectional diagramalong the longitudinal center line 'l-Cl'lis furnace is particularlyintended for the reduction of oxid of zinc combined with carbon as thereagent, whereby, when adequately hosted the following representativereaction ensues, namely:

or less limited amount of residual matter is l diiiiculty which isencountered in e successful commercial result.

Specification of Letters Eatent.

Thomson, :2.-

Putented Dec. 9, 1913.

Serial 1-10. 239,792.

The heat necessary for decomposingthe charge is preferably derived froman electric current passed through a broken bed of carbon resistor, thecharge being acted upon by direct conduction of heat.

The bed of carbon. resistor H is disposed along the longitudinal centerof the furnace. its ends being interpolated between terminals 4 to whichthe electric current is tluoted by copper electrodes 5. This resistersustained bye series of spaced grate bars 6 which in turn rest uponledges, T, formed in a shallow tomped casing R; Beneath the grate barsthere is a sump n in which the inert residual matter 8 is collected. inthe les 9 of the casing, which coniine or form the boundaries of theresister, are a. series of 0penin'gs,-slits or ports 10 whose bottomsextend down to the ledges upon which the grate bars are supported. '5 hetops of the said ports are covered by refractory plates, as 12. Twocondensers J, J are employed. och being parallel and immediatelyadjacent to the side walls of the resistor cusing, hich in fact providea. part oil the inner walls of the condensing chambers.

The resistor carbon is of sufiioient depth to fully cover the inneropenings of the ports 10. charge material P is fed to inc the upper faceor the resistor through verticul galleries Fig. 3, formed by a series oispaced slabs or plates 14. The volatilized products of the reaction passdown into and through the transverse Zones under the slabs or plates,and from which zones it may flow in various directions through thecarbon to the grate bur spaces 15 and thence to the ports as in themanner indicated by the flow arrows 16. The residue may either sift orpercolui'c or be poked down through the resistor and fall into the sumpthrough the grate bur spaces as indicated by the arrows 17. Afterpassing through the bed of carbon resistor the fume and gas will be freeof any pernicious oxidizing agent such as CO and will also be atsubstantially the temperature of the resistor and hence the outflow fromthe ports 10 into the free spaces 6, c of the condensers will maintain atemperature therein approximating that of the sidewalls of the resistorcasing. To realize this condition to the utmost extent the material ofthe outer walls 18, 18 of the condensers should be of the best non.-heat-conductive refrac tories and the same applies to the cover tiles 19and also the overlying bricks. The latter may further more be sheathedwith charge material to seal the joints and afford additional heatinsulation.

An advantage of the foregoing construction and arrangement is that theheat necessarily carried away by the fume and gas assists in maintainingthe temperature of the resistor casing walls and thus prevents amaterial direct and additional conduction of heat away from the sides ofthe re sistor itself, and consequently there Will'be little or nothermalloss from the resistor. Moreover, the right and left handcondenseas act as thermal blankets to the cen .trally disposed resistorand also aid in main t'aining' a minimum thermal loss from the resistor.

The condensation of the clean fume received in the spaces 6,i's-efiected by causing it together With its entraining en velo'p of COto pass downwardly throurh several series of slits or spaces 20 formed'by cross-stacked and preferably staggered plates 21 set on edge andarranged longitudinally along and transversely of the condenser chambercasings. These plates usu ally comprise a large percentage of carbon orgraphite and afford a large superficial surface and also provide anample for primarily absorbing heat from the vola-' tilized products ofthe reaction and then rapidly and progressively conducting away the saidheat.

The latter condition is obtained by building the battery of condensingplates upon a series of supports 23 that are partially Inersed in a bathof liquid zinc 24 which is maintained at about a constant depth inbottom of the condensing chamber and the temperature of which bath isunder control. The temperature of the said bath is con-- trolledaccording to the rate of evolution of fume and gas by causing acirculation of hot gases or of cooling air, as the need may be, throughthe chambers or times Y, 1", situated beneath the condensers. Thethermal conditions may be illustrated by assuming a case, thus: The bathmust be maintained at a safe temperature aboye its freezing point whichis about 7 Let this temperature of the bath betaken as 850 Now, if thefume and gas in the spaces 6, c, as they enter the slits has atemperature of say 2300 F. and if the upper edges of the plates have atemperature of say 2200 F. then there will be a difference of I350 F.

,hetyyeen the upper series of plates and the '60- mersed in the bath. Asit will be suificient .ifthe fume and gas is chilled to atemperaportions of the supports 23 which are imtureof say 1050 F. thismeans a drop of 1250 and leaves a reserve chilling difference in thecondenser of 100 F. between reac es the upper plates and the top of thebath. The final exit of any residual fume and the original CC from thelower series of plates is in the form of narrow sheets, which inipingedirectly upon the surfaces of the baths and which react and flow rightand left to subsequently ind through the openings or ports 25., 26, intothe large chamber or tine X beneath the resistor, thence to atmosphereby a tube or tubes During the slow transit through the large chamber Xthe stored heat in the gas acts to conserve the temperature in the sump.

The condenser plates n1 y be narrow or wide, thick or than nd set toprovide slits oi. any desired iviiflth. nit it desirable that the afigs-to area of the slits shall be such as to insure a lov; vclocit, offlow there}, through. The spacing of the longitudinal and transverseplates may be such as to obtain an equal flow area through each seriesor the velocity may be more rapid through one series than the other. theflow area is uniform from top to bottom the velocity oi? flow willconstantly diminish, due to the reduction of volume as thetemperaturelo'wers, hence the plates may be stacked so that the spacesbetween them will be lessened and so that the number or thickness of theplates in a series may be increased grcssively downward.

' In design having central resistor combined with compound condensers itis advisable and quite essential that the evolved products of thereaction shall have a primary free escape from the seat or seats of thereaction, that the heat developed in the resistor shall be largelyutilized precisely at the seat or seats of the reaction, that vol izedproducts of the reaction shall be delivered into the condensers in suchmanner as to insure a uniform dispersion volnine and 'ilOW through thecondensing systern, that the velocity of flow imparted to the fume ancgas shall be relatively slow, that large or objectionable baclcpressureof fume and. gas shall not be set up against the seat or seats oi"; thereaction and that the means for absorbing and dissipating the storedheat 'in the fume and gas shall be adaptable to the rate atwhich theyare evolved. These features, jointly and severally, are herein :tullydisclosed, but it is manifest; that the improvements herein set forthare not limited to the precise construction and arrangement shownanddescribed, as they may be embodied in various forms and modifications,and that various changes and alterations in the manner and method ofWorking may be made Without departing from the spirit and essence of theinvention.

What I claim is:

of-carbon resistor supported on a grate osoeee above an underlyingresidue sump and located between confining side walls having a series oflateral openings or ports leading to condensers on opposite sides of theresistor.

2. An electric zinc smelting furnace having a bed-of-carbon resistorsupported on spaced grate members above a residue sump, condenserslocated on opposite sides of the resistor, a resistor rota iing sidewall providing'a part of the inner wall of the condenser and havingopenings therein through which fumes can pass directly from the resistorto the condensers.

3. A combined electric furnace and condenser having a resistor, resistorretaining walls contiguous to the sides of the resistor, said wallsbeing provided with openings through which fumes can pass directly fromthe resistor to the upper portion of the condensers which are arrangedon opposite side of the resistor. 7

4. An electric furnace having a resistor supported on spaced grate barsbelow which is a sump, the resistor beingretained in place by wallshaving therein openings for conducting the fumes and gases t a condenseror condensers, the top portions of said openings being below the top ofthat portion of the resistor adjacent thereto and the lower portion ofsaid openings communicating with the space between the grate barswhereby any fumes or gases which pass through the resistor to the spacebetween the grate bars can flow directly through said openings to thecondenser orcondensers.

5. In an electric zinc smeltingfurnace, a resistor casing having aseries of resistor supporting spaced grate bars and perforated sidewalls which form a part of the walls of.

condenser-s along the sides of the said casing. G. In an electricfurnace of the resistor type, resistor casing side walls havingtransverse ports, the upper portions of the inner portions of which arepartially closed by the sides of said walls for receiving thevolatilized products of the reaction after they will have-passed throughthe said resistor.

8. A condenser combined with a suitable source of supply of zinc fume orof fume and gas, said condenser having a battery of spaced cross stackedand staggered plates sustained by supports at least partially immersedin a bath of liquid metal.

9. An electric zinc furnace adapted. to effeet the reaction ofZnO-l-C,-and side condensers for receiving the volatilized products ofthe reaction and provided with cross stacked plates set edgewise to thedirection of the flowing fume and 10. In an electric zinc furnace, aresistor having subdivided zones through which the volatilized and theinert products of the reaction respectively flow and gravitate, combinedwith perforated sidewalls forming portions of the inner walls ofcondensing chambers, a series of spaced grate bars and an underlyingsump.

11. In a furnace and condenser, a resistor for efiecting substantiallythe ZnO+C re action, the volatilized products thereof being passed intoand through the said resistor, combined with one or more condenserscomprising a system of heat absorbing and heat conducting plates, theupper portions of which have a temperature approximating that of thefume and gas and the lower portions of which have a temperatureapproximating that of liquid zinc.

12. A combined electric furnace and condenser having a resistor above asump, condensers on opposite sides of theresistor arranged to receiveinthe upper portions thereof the products of the reaction, and a chamberor chambers below the sump into which the residual gases from thecondenser pass prior to their exit to the atmosphere.

13. A zinc condensing apparatus having a plurality of condensingchambers provided therein with spaced cross stacked members located overbaths of molten zinc so that fumes passing, downwardly through saidstack will impinge against the top surface of the bath, and a chamberunder the sump for receiving the residual gases from the condensingchambers.

14. A zinc condenser having a plurality of condensing chambers providedwith liquid baths at the bottom, a common chamber into which theresidual gases from the condensers flow and provided with a commoncooling or heating means below the liquid baths.

This specification signed and witnessed this 31 day of December A. D.1913.

JOHN THOMSON.

Signed in the presence of EDWIN A. PACKARD, D. IIAROLD BUSH.

